Checked out the new AppStore layout. The changes seem mostly cosmetic, though I did notice that when you download an app, you are no longer forced to exit the app store.
Is it possible that you need to upgrade your iTunes to the latest version first?
Yes. Only the latest version of iTunes supports iOS 6.
ETA: Though for me the latest version of iTunes keeps crashing. Since Candlelight
has also expressed trouble with it, it's likely not just me, so it's probably best to update your device wirelessly.